[S390] Automatic IPL after dump

Provide new shutdown action "dump_reipl" for automatic ipl after dump.

Signed-off-by: Frank Munzert <munzert@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

5 files changed, 86 insertions, 24 deletions

diff --git a/arch/s390/include/asm/lowcore.h b/arch/s390/include/asm/lowcore.h
index f3720defdd16..ee4b10ff9387 100644
--- a/arch/s390/include/asm/lowcore.h
+++ b/arch/s390/include/asm/lowcore.h
@@ -111,7 +111,7 @@
 
 #define __LC_PASTE                      0xE40
 
-#define __LC_PANIC_MAGIC                0xE00
+#define __LC_DUMP_REIPL                 0xE00
 #ifndef __s390x__
 #define __LC_PFAULT_INTPARM             0x080
 #define __LC_CPU_TIMER_SAVE_AREA        0x0D8
@@ -286,12 +286,14 @@ struct _lowcore
         __u64        int_clock;                /* 0xc98 */
         __u8         pad11[0xe00-0xca0];       /* 0xca0 */
 
-        /* 0xe00 is used as indicator for dump tools */
-        /* whether the kernel died with panic() or not */
-        __u32        panic_magic;              /* 0xe00 */
+        /* 0xe00 contains the address of the IPL Parameter */
+        /* Information block. Dump tools need IPIB for IPL */
+        /* after dump.                                     */
+        __u32        ipib;                     /* 0xe00 */
+        __u32        ipib_checksum;            /* 0xe04 */
 
         /* Align to the top 1k of prefix area */
-        __u8         pad12[0x1000-0xe04];      /* 0xe04 */
+        __u8         pad12[0x1000-0xe08];      /* 0xe08 */
 #else /* !__s390x__ */
         /* prefix area: defined by architecture */
         __u32        ccw1[2];                  /* 0x000 */
@@ -379,12 +381,14 @@ struct _lowcore
         __u64        int_clock;                /* 0xde8 */
         __u8         pad12[0xe00-0xdf0];       /* 0xdf0 */
 
-        /* 0xe00 is used as indicator for dump tools */
-        /* whether the kernel died with panic() or not */
-        __u32        panic_magic;              /* 0xe00 */
+        /* 0xe00 contains the address of the IPL Parameter */
+        /* Information block. Dump tools need IPIB for IPL */
+        /* after dump.                                     */
+        __u64        ipib;                     /* 0xe00 */
+        __u32        ipib_checksum;            /* 0xe08 */
 
         /* Per cpu primary space access list */
-        __u8         pad_0xe04[0xe38-0xe04];   /* 0xe04 */
+        __u8         pad_0xe0c[0xe38-0xe0c];   /* 0xe0c */
         __u64        vdso_per_cpu_data;        /* 0xe38 */
         __u32        paste[16];                /* 0xe40 */
 
@@ -433,8 +437,6 @@ static inline __u32 store_prefix(void)
         return address;
 }
 
-#define __PANIC_MAGIC           0xDEADC0DE
-
 #endif
 
 #endif
diff --git a/arch/s390/include/asm/system.h b/arch/s390/include/asm/system.h
index 3a8b26eb1f2e..3f2ccb82b863 100644
--- a/arch/s390/include/asm/system.h
+++ b/arch/s390/include/asm/system.h
@@ -458,6 +458,22 @@ static inline unsigned short stap(void)
         return cpu_address;
 }
 
+static inline u32 cksm(void *addr, unsigned long len)
+{
+        register unsigned long _addr asm("0") = (unsigned long) addr;
+        register unsigned long _len asm("1") = len;
+        unsigned long accu = 0;
+
+        asm volatile(
+                "0:\n"
+                "       cksm    %0,%1\n"
+                "       jnz     0b\n"
+                : "+d" (accu), "+d" (_addr), "+d" (_len)
+                :
+                : "cc", "memory");
+        return accu;
+}
+
 extern void (*_machine_restart)(char *command);
 extern void (*_machine_halt)(void);
 extern void (*_machine_power_off)(void);
diff --git a/arch/s390/kernel/ipl.c b/arch/s390/kernel/ipl.c
index 2dcf590faba6..5663c1f8e46a 100644
--- a/arch/s390/kernel/ipl.c
+++ b/arch/s390/kernel/ipl.c
@@ -56,13 +56,14 @@ struct shutdown_trigger {
 };
 
 /*
- * Five shutdown action types are supported:
+ * The following shutdown action types are supported:
  */
 #define SHUTDOWN_ACTION_IPL_STR         "ipl"
 #define SHUTDOWN_ACTION_REIPL_STR       "reipl"
 #define SHUTDOWN_ACTION_DUMP_STR        "dump"
 #define SHUTDOWN_ACTION_VMCMD_STR       "vmcmd"
 #define SHUTDOWN_ACTION_STOP_STR        "stop"
+#define SHUTDOWN_ACTION_DUMP_REIPL_STR  "dump_reipl"
 
 struct shutdown_action {
         char *name;
@@ -146,6 +147,7 @@ static enum ipl_method reipl_method = REIPL_METHOD_DEFAULT;
 static struct ipl_parameter_block *reipl_block_fcp;
 static struct ipl_parameter_block *reipl_block_ccw;
 static struct ipl_parameter_block *reipl_block_nss;
+static struct ipl_parameter_block *reipl_block_actual;
 
 static int dump_capabilities = DUMP_TYPE_NONE;
 static enum dump_type dump_type = DUMP_TYPE_NONE;
@@ -835,6 +837,7 @@ static int reipl_set_type(enum ipl_type type)
                         reipl_method = REIPL_METHOD_CCW_VM;
                 else
                         reipl_method = REIPL_METHOD_CCW_CIO;
+                reipl_block_actual = reipl_block_ccw;
                 break;
         case IPL_TYPE_FCP:
                 if (diag308_set_works)
@@ -843,6 +846,7 @@ static int reipl_set_type(enum ipl_type type)
                         reipl_method = REIPL_METHOD_FCP_RO_VM;
                 else
                         reipl_method = REIPL_METHOD_FCP_RO_DIAG;
+                reipl_block_actual = reipl_block_fcp;
                 break;
         case IPL_TYPE_FCP_DUMP:
                 reipl_method = REIPL_METHOD_FCP_DUMP;
@@ -852,6 +856,7 @@ static int reipl_set_type(enum ipl_type type)
                         reipl_method = REIPL_METHOD_NSS_DIAG;
                 else
                         reipl_method = REIPL_METHOD_NSS;
+                reipl_block_actual = reipl_block_nss;
                 break;
         case IPL_TYPE_UNKNOWN:
                 reipl_method = REIPL_METHOD_DEFAULT;
@@ -1332,6 +1337,48 @@ static struct shutdown_action __refdata dump_action = {
         .init   = dump_init,
 };
 
+static void dump_reipl_run(struct shutdown_trigger *trigger)
+{
+        preempt_disable();
+        /*
+         * Bypass dynamic address translation (DAT) when storing IPL parameter
+         * information block address and checksum into the prefix area
+         * (corresponding to absolute addresses 0-8191).
+         * When enhanced DAT applies and the STE format control in one,
+         * the absolute address is formed without prefixing. In this case a
+         * normal store (stg/st) into the prefix area would no more match to
+         * absolute addresses 0-8191.
+         */
+#ifdef CONFIG_64BIT
+        asm volatile("sturg %0,%1"
+                :: "a" ((unsigned long) reipl_block_actual),
+                "a" (&lowcore_ptr[smp_processor_id()]->ipib));
+#else
+        asm volatile("stura %0,%1"
+                :: "a" ((unsigned long) reipl_block_actual),
+                "a" (&lowcore_ptr[smp_processor_id()]->ipib));
+#endif
+        asm volatile("stura %0,%1"
+                :: "a" (cksm(reipl_block_actual, reipl_block_actual->hdr.len)),
+                "a" (&lowcore_ptr[smp_processor_id()]->ipib_checksum));
+        preempt_enable();
+        dump_run(trigger);
+}
+
+static int __init dump_reipl_init(void)
+{
+        if (!diag308_set_works)
+                return -EOPNOTSUPP;
+        else
+                return 0;
+}
+
+static struct shutdown_action __refdata dump_reipl_action = {
+        .name   = SHUTDOWN_ACTION_DUMP_REIPL_STR,
+        .fn     = dump_reipl_run,
+        .init   = dump_reipl_init,
+};
+
 /*
  * vmcmd shutdown action: Trigger vm command on shutdown.
  */
@@ -1421,7 +1468,8 @@ static struct shutdown_action stop_action = {SHUTDOWN_ACTION_STOP_STR,
 /* action list */
 
 static struct shutdown_action *shutdown_actions_list[] = {
-        &ipl_action, &reipl_action, &dump_action, &vmcmd_action, &stop_action};
+        &ipl_action, &reipl_action, &dump_reipl_action, &dump_action,
+        &vmcmd_action, &stop_action};
 #define SHUTDOWN_ACTIONS_COUNT (sizeof(shutdown_actions_list) / sizeof(void *))
 
 /*
@@ -1434,11 +1482,11 @@ static int set_trigger(const char *buf, struct shutdown_trigger *trigger,
                        size_t len)
 {
         int i;
+
         for (i = 0; i < SHUTDOWN_ACTIONS_COUNT; i++) {
                 if (!shutdown_actions_list[i])
                         continue;
-                if (strncmp(buf, shutdown_actions_list[i]->name,
-                            strlen(shutdown_actions_list[i]->name)) == 0) {
+                if (sysfs_streq(buf, shutdown_actions_list[i]->name)) {
                         trigger->action = shutdown_actions_list[i];
                         return len;
                 }
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index c5cfb6185eac..8fdf08379ce9 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -86,6 +86,10 @@ volatile int __cpu_logical_map[NR_CPUS]; /* logical cpu to cpu address */
 int __initdata memory_end_set;
 unsigned long __initdata memory_end;
 
+/* An array with a pointer to the lowcore of every CPU. */
+struct _lowcore *lowcore_ptr[NR_CPUS];
+EXPORT_SYMBOL(lowcore_ptr);
+
 /*
  * This is set up by the setup-routine at boot-time
  * for S390 need to find out, what we have to setup
@@ -434,6 +438,7 @@ setup_lowcore(void)
         lc->vdso_per_cpu_data = (unsigned long) &lc->paste[0];
 #endif
         set_prefix((u32)(unsigned long) lc);
+        lowcore_ptr[0] = lc;
 }
 
 static void __init
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 2d337cbb9329..e279d0fbbbe8 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -50,12 +50,6 @@
 #include <asm/vdso.h>
 #include "entry.h"
 
-/*
- * An array with a pointer the lowcore of every CPU.
- */
-struct _lowcore *lowcore_ptr[NR_CPUS];
-EXPORT_SYMBOL(lowcore_ptr);
-
 static struct task_struct *current_set[NR_CPUS];
 
 static u8 smp_cpu_type;
@@ -82,9 +76,6 @@ void smp_send_stop(void)
         /* Disable all interrupts/machine checks */
         __load_psw_mask(psw_kernel_bits & ~PSW_MASK_MCHECK);
 
-        /* write magic number to zero page (absolute 0) */
-        lowcore_ptr[smp_processor_id()]->panic_magic = __PANIC_MAGIC;
-
         /* stop all processors */
         for_each_online_cpu(cpu) {
                 if (cpu == smp_processor_id())